1. Field of the Invention
The present invention is in the field of loose leaf binders and the like which can be folded into an easel-type structure in which the pages of the notebook are positioned at a convenient angle for viewing, the easel-type structure being mechanically rigid and resistant to twist.
2. Description of the Prior Art
There have been numerous suggestions in the prior art of loose leaf type binders which can be folded into an easel-type structure. For example, in U.S. Pat. No. 2,883,209 there is described a combined loose leaf binder and display device employing a series of panels in combination with a stiff wire which holds the loose leaf binder in the display position.
In U.S. Pat. No. 3,199,897 there is described another kind of easel-type device employing strips of spring steel as braces for holding the easel in its display position.
U.S. Pat. No. 3,224,792 is directed more specifically to a book structure which is capable of being supported in an upright or angular position by providing a leg or prop extending coextensively with the back of the book structure and hingedly secured thereto.
In U.S. Pat. No. 4,015,863 there is disclosed an easel-type binder utilizing a flap connected to a strip underlying the ring mechanism, the flap being foldable into a position in which it fits into a groove and holds the easel in its upright position.